The detailed mechanism of assembly of mammalian and other viruses will be investigated by physical-chemical techniques. Specifically, the elementary step kinetics of the assembly of Mengo and Tobacco Mosaic Viruses will be studied using stopped-flow and temperature-jump relaxation kinetics methods. The assembly mechanisms of these two viruses, examples of icosahedral and tubular viruses, will be analyzed with the following question in mind: are there general kinetic principles governing the assembly of these two structural classes of viruses? A concurrent investigation of the regulation of the biosynthesis of Mengo virus will allow us to inquire into the mechanism by which virus assembly is coordinated in time with protein and nuclei acid synthesis.